Population means all individuals of the same species that occupy a certain space for some time. Population size is the sum of the size of individuals in populations, and is the basis of calculating population density, birth rate, mortality, immigration rate and emigration rate. On one hand, observation of wildlife population size is conducive to revealing the changing rule of wildlife populations and providing basic data support for wildlife protection, and on the other hand, is also conducive to analyzing natural and social factors that influence distribution of animal populations and providing necessary basis for protecting and restoring the ecosystems and promoting economic and social sustainable development around habitats.
Observation and counting of the wildlife populations and the population size are mainly conducted through manual physical counting and estimation for a long time. These methods are greatly influenced by experience of observers, generate counting results which are not at the same time point, are difficult to realize observation of hidden individuals and consume a great number of human power, material resources and time in an investigation. These methods may result large errors and low economy efficiency. Maturity and application of high-resolution remote sensing imager provides a new thought for overlooking the wildlife from an orthogonal angle to obtain features of wildlife distribution patterns at the same time point.